Hello again,
A friend and I did some work validating Simbrain 2's Izhikevich implementation against the matlab scripts, including the tonic spiking case. We did not find any discrepancies, so perhaps you can send more detail about the issue you ran into?
One thing that was an issue is that the time-step in Simbrain does not, by default, match the tau parameter in the matlab scripts. So that should be set to .2
Attached is a network that simulates tonic spiking with input current of 14.
Let me know if you have more questions or run into problems.
- Jeff
TonicSpiking_A.net 
